Worked on the NixOS/nix repository to address deprecation issues in Docker configuration, focusing on maintaining compatibility with evolving Nix language standards. Delivered a targeted bug fix by replacing the deprecated mapAttrsFlatten function with mapAttrsToList in docker.nix, which reduced deprecation warnings and improved future maintainability. Applied code refactoring techniques to enhance code health and ensure long-term stability of the configuration. All changes were consolidated into a single, traceable commit, supporting clear project history. Utilized expertise in the Nix language and code refactoring to align the repository with current best practices, minimizing future maintenance overhead and compatibility risks.